Platelets Do More than Help Blood Clot – Just Ask the Immune System
Platelets are known for their role in forming blood clots, but more and more research shows that platelets help control our immune system as well. In the last five to 10 years, scientists have found that platelets either initiate or accelerate the body’s immune response in a wide range of inflammatory diseases, including atherosclerosis (when plaque builds up inside the arteries), arthritis and transplant rejection.
In a study published today in The Journal of Clinical Investigation, Craig Morrell, DVM, Ph.D., discovered another important function of platelets: Keeping immune cells in balance. In a group of mice that received heart transplants, those with low platelet counts had heightened immune responses to the transplant, producing an unusually high number of immune cells called T helper 17 cells or Th17 cells. Superfluous immune cells led to transplant rejection in most animals.
Morrell, an associate professor at the University’s Aab Cardiovascular Research Institute, says the idea that platelets keep immune cells in check is a new concept and his team is considering what it means for patients. For example, if a liver transplant patient has a low platelet count physicians may increase platelet levels before the transplant in order to limit rejection. The findings may influence the treatment of other conditions that may involve T helper 17 cells, such as arthritis, asthma and atherosclerosis as well.
The study was funded by the National Heart Lung and Blood Institute at the National Institutes of Health and the American Heart Association. In addition to Morrell’s team at the Cardiovascular Research Institute, scientists from UR’s Department of Microbiology and Immunology, the Children’s Hospital of Philadelphia and the Department of Pediatrics at the University of Pennsylvania contributed to the study.
Read the full study here.
Emily Boynton |